Ease timeline zoom level restriction

[trappar]

Implements the feature I suggested here: #314

What

The maximum zoom level has been increased. Now, the maximum zoom is the point the point where the entire sequence is represented by a single grid cell.

Why

Personally I never found this limitation to make sense. Why stop me from zooming out beyond my clip? If zoom only affected visibility, it would make sense... but zoom also affects entered note length. By allowing more freedom to zoom, you can access instant entry of note lengths that were previously not possible.

For example, this makes it super quick to enter basic chord progressions.

Given a brand new project, to create a 4 chord progression where each chord lasts for 1-bar:

1. Zoom all the way out to 1 bar per column (one quick twist)
2. Expand the sequence to 4 bars (3 clicks on the horizontal control)
3. Enter your 4 chords on the 4 active grid columns.

Prevously the fastest way I know to do this would be:

1. Hit shift + horizontal encoder twice (bit fiddly remembering that this equates to creating a 4-bar loop)
2. Create chords via pressing, holding, and pressing the note end (this takes 2x the number of presses as above)

Total inputs to make a 4-chord tri-tone chord progression with both methods:

• Restricted zoom: 27
• Unrestricted zoom: 16

Notes

As a community feature?

I don't think this needs to be a community feature for the following two reasonsL

1. It only eases an existing restriction.
2. It does so in a way that shouldn't annoy users, thanks to the delay I introduced when crossing the previous max zoom level threshold. If you're zoomed in and want to return to the previous max zoom level, you can still hold the horizontal encoder down and quickly turn it to the left - it will catch at the prior max zoom for half a second.

What even is "max zoom" anymore?

This PR degrades the ability to understand what clip's getMaxZoom means. The clip's max zoom isn't actually the timeline's max zoom anymore.

Ideally I would have liked to have updated the actual behavior of Clip::getMaxZoom() in src/deluge/model/clip/clip.cpp, but that function is used in many more places than the timeline.

[github-actions]

Test Results

28 tests  ±0   28 ✅ ±0   0s ⏱️ ±0s
 4 suites ±0    0 💤 ±0 
 4 files   ±0    0 ❌ ±0 

Results for commit 5eab63c. ± Comparison against base commit 0ed09a2.

♻️ This comment has been updated with latest results.

[m-m-adams]

Small nit but lgtm. As mentioned on discord I'm good to merge as is (in community features) or to add a "catch" at the old max zoom level and just have the feature always on

[sapphire-arches]

2 minor nitpicks and this should get an entry in CHANGELOG.md, then lgtm

[YPares]

This feature doesn't seem present in the 1.1 firmware. Is it gated behind a setting?

[trappar]

This feature doesn't seem present in the 1.1 firmware. Is it gated behind a setting?

No, this will be in 1.2. You can try nightly if you want to use it now.